diff --git a/src/main/java/com/github/creme332/controller/CanvasController.java b/src/main/java/com/github/creme332/controller/CanvasController.java
index a79475ac..4cb548b7 100644
--- a/src/main/java/com/github/creme332/controller/CanvasController.java
+++ b/src/main/java/com/github/creme332/controller/CanvasController.java
@@ -4,6 +4,8 @@
 import java.awt.event.MouseWheelEvent;
 import java.awt.geom.Line2D;
 import java.awt.geom.Point2D;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
 import java.awt.Point;
 import java.awt.event.ComponentAdapter;
 import java.awt.event.ComponentEvent;
@@ -15,7 +17,7 @@
 import com.github.creme332.model.ShapeWrapper;
 import com.github.creme332.view.Canvas;
 
-public class CanvasController {
+public class CanvasController implements PropertyChangeListener {
     private Canvas canvas;
 
     /**
@@ -35,6 +37,8 @@ public CanvasController(AppState app, Canvas canvas) {
         this.canvas = canvas;
         this.model = app.getCanvasModel();
 
+        app.addPropertyChangeListener(this);
+
         canvas.addComponentListener(new ComponentAdapter() {
             @Override
             public void componentResized(ComponentEvent e) {
@@ -175,4 +179,16 @@ private void resetCanvasView() {
         model.setCellSize(CanvasModel.DEFAULT_CELL_SIZE);
         canvas.repaint();
     }
+
+    @Override
+    public void propertyChange(PropertyChangeEvent e) {
+        final String propertyName = e.getPropertyName();
+        // if mode has changed while a shape is being drawn
+        if ("mode".equals(propertyName) && currentWrapper != null) {
+            // erase incomplete shape
+            model.getShapes().remove(currentWrapper);
+            currentWrapper = null;
+            canvas.repaint();
+        }
+    }
 }
diff --git a/src/main/java/com/github/creme332/model/AppState.java b/src/main/java/com/github/creme332/model/AppState.java
index 1d8352d3..e0e57a6b 100644
--- a/src/main/java/com/github/creme332/model/AppState.java
+++ b/src/main/java/com/github/creme332/model/AppState.java
@@ -128,6 +128,7 @@ public CanvasModel getCanvasModel() {
 
     public void addPropertyChangeListener(PropertyChangeListener listener) {
         support.addPropertyChangeListener("sidebarVisibility", listener);
+        support.addPropertyChangeListener("mode", listener);
     }
 
     public boolean getSideBarVisibility() {